ᐅ Insulation with Expanded Polystyrene (EPS) on Lightweight Expanded Clay Aggregate (LECA) Walls

Hello, we would like to build a prefabricated house using solid construction with the base material Bähton (Liapor). Unfortunately, the suppliers only offer insulation with polystyrene foam. We have doubts about whether polystyrene insulation is really up to date. We would appreciate any experiences, studies, or alternative suggestions! Thank you very much and best regards

Moni1985 schrieb:

We have doubts whether insulation with styrofoam is really up-to-date?!

Yes, it is absolutely up-to-date and just as common as a monolithic wall construction. It has been used for 50 years and is practically the go-to solution for renovations of older buildings.

Moni1985 schrieb:

Hello, we would like to build a prefabricated house using solid construction with Liapor-based concrete. Unfortunately, the suppliers only offer insulation using polystyrene.

A "prefab" house made from Liapor – I assume you mean panel construction? Then ask your supplier when and how the insulation is applied: during the production of the panels, or on site; fully adhered, already placed in the mold, or mechanically fastened? If the insulation is a composite material with the outer shell as the insulation, my “11ant Steinemantra” roughly means that for warranty reasons, it would be unwise to change the wall assembly’s composition. If it’s a sandwich panel, you probably won’t be offered that option at all.

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11ant schrieb:

A prefabricated house made of Liapor – I assume it’s panel construction? – then ask your supplier when and how the insulation is applied: during the panel manufacturing, or on site; fully bonded, already laminated into the panel, or mechanically attached?
If it’s a composite material with the insulation as the outer shell, my “11ant masonry mantra” basically says that for warranty reasons it would be unwise to alter the wall build-up formula. If it’s even a sandwich panel, you probably won’t be offered the option anyway.

Thanks for the input. The walls including insulation are prefabricated in the factory, and we could choose wood fiber insulation for an additional cost.
The insulation material used is Styrodur, which is somewhat higher quality than Styrofoam. However, I am concerned whether the building will still be vapor permeable.
Thanks and best regards

Moni1985 schrieb:

The walls, including insulation, are prefabricated at the factory; for an additional cost, we could also choose wood fiber insulation.
The insulation material is Styrodur, which is supposedly a bit higher quality than Styrofoam. However, I’m concerned whether the building will still be breathable with this option.

If breathability is important to you and the manufacturer offers the option, then choose the wood fiber insulation.

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https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/

Moni1985 schrieb:

Hello, we would like to build a prefabricated house using solid construction with the base material Bähton (Liapor).
Unfortunately, the providers only offer insulation with Styrofoam. We have doubts about whether Styrofoam insulation is really up to date?! We would appreciate experiences, studies, or alternative suggestions!
Thank you very much and best regards

We had a provider who works entirely without additional external insulation. The walls there are 42 or 50 cm (17 or 20 inches) thick and do not require any extra layers. They don’t look like concrete walls at all, but rather like a porous material. A standard plaster is applied on the outside, and the plaster on the inside is already done at the factory. Check out raumbuild, I believe they build nationwide and focus on sustainability, ecology, and the healthiness of all materials used throughout the entire house—not just the walls.
We have the 50 cm (20 inch) wall and a KfW 55 energy standard.